Some wheelchair footrests of the types known in the art comprise a pair of shafts extending forwards from lateral sides of a main frame, and a pair of foot plates pivoted to the shafts. The foot plates are allowed to swivel between their horizontal (closed) positions facing close to each other and their upright idle (open) positions. However, a retention mechanism will prevent each foot plate from any unintentional fall from its open upright position to closed horizontal position. Such a mechanism usually comprises a spring, threaded members and/or the like intervening between the pivoting portions of foot plate and shaft, thereby imparting thereto a strong frictional resistance.
In use, whenever getting on or off the wheelchair, every handicapped or aged user or any assistant or helper attending on the user must use their hands or feet to put the foot plates out of the way. In detail, the foot plates are forced to their upright open position before the user sits on the wheelchair. He or she will then turn the foot plates towards each other to take the horizontal and closed (operative) position until they lie still to support his or her feet.
Usually, such a direct and manual or kicking operation to open or close the foot plates is not so easy to the user or helper. In particular, if the user sitting on the wheelchair is a handicapped or aged person, it may be considerably difficult to bend his or her body forwards and deeply to handle the foot plates. In a case wherein a helper operates the foot plates, he or she has to bow or squat down in front of the wheelchair in order to rotate the foot plates. This causes a pain to him or her, and a narrow forward space will make the operation very difficult. Further, bare hands of the user or helper touching the foot plates will catch an amount of dirt and a number of bacteria that souls of his or her shoes have picked up and collected from streets, hospital floors or lavatories. This is a hygienic problem that may spread any infectious diseases in hospitals, so that the wheelchair of the described types have been washed and sterilized periodically.
Some proposals have been made to resolve or diminish the drawback and problems inherent in the prior art wheelchairs. In those proposals, a manual lever is disposed on one side of a main frame, and an actuator operatively connects the lever to each foot plate. When the foot plates are opened or closed, the user need no longer touch them directly with his or her bare hands. Such manipulation devices as shown in the Patent References 1 and 2 (Japanese Patent Laying-Open Gazette Nos. 2003-310664 and 2005-192959 respectively) have assisted the user to easily get on or off a wheelchair and have facilitated the helper's work.
The manipulation device disclosed in Patent Reference 1 is intended to operate foot plates in a wheelchair, and comprises a pair of urging means (e.g., coiled springs) for always biasing upwards the foot plates to turn towards their upright open position. This device further comprises a pair of actuating means (e.g., wires) to operatively connect each foot plate to a manual lever. Those wires act on both the foot plates so as to turn them against the coiled springs towards a transverse and operative (closed) position where they lie close to each other.
The wheelchair described in Patent Reference 1 is somewhat complicated in structure due to the urging means such as coiled springs for always biasing upwards the foot plates towards their upright open (idle) position. Besides, it would be difficult to wash out dust and bacteria that have migrated from the foot plates to the urging means. Wrong operation of the manual levers may possibly cause the urged foot plates to leap up to the upright open (idle) position, thus bring about some difficulty in use. In addition, the actuating means are slack wires to permit any intended change in height of each foot plate. Therefore, it any foreign matter caught the slack wires, the manual levers would make a malfunction.
The foot plate manipulating device described in Patent Reference 2 had been proposed previously by the present inventors. However, it had not suggested any details with respect to structure of an actuating means for connecting each foot plate to a manual lever. The present invention was accomplished through a number of trials and researches made by use to render feasible the device of Reference 2.